This FAQ is for Stata 11. It is not relevant for more recent versions.
Why do I get the error message "no room to add more observations"?
Allocating memory in Stata
Jeremy B. Wernow, StataCorp
June 2000; minor revision March 2001
You need to allocate more memory to Stata. You can do this by typing
set memory #,
where # is the amount of memory you want to allocate.
set memory 20000
set memory 20m
Both commands will allocate 20 megabytes of memory.
There are two important considerations when deciding how much memory to
- Make sure that you allocate an amount of memory that is larger than the file
that you are using. If your file is 30 megabytes, you may want to allocate
50 megabytes of memory to Stata. Stata will need the extra room to perform
any commands or calculations. A good rule of thumb for large files is to
allocate roughly 50% more memory than the size of your file. If you are
using smaller files (< 10 megabytes), then allocating 15 megabytes on a PC with
128 megabytes of RAM is a good general guideline.
- Make sure that you do not allocate too much memory because your
computer will not have enough memory (RAM) left to perform other tasks.
For example, if you only have 256 megabytes of RAM, then you should not
allocate more than that. If you have a file that is larger than the amount
of RAM installed on your computer, you will have to acquire more memory,
work on a more powerful computer, or sacrifice speed by using virtual
FAQ: How can I use a dataset that is larger than the available RAM?
for more information
about virtual memory and Stata.
To read more about memory usage in Stata, see appendix B in the Getting
Started with Stata manual.